This invention relates to an outboard motor and more particularly to an improved flushing and tell tale arrangement for the cooling systems for outboard motors.
As is well known, outboard motors normally have their engines cooled by a liquid cooling system that draws water from the body of water in which the watercraft is operating and which discharges it back to the body of water after it has passed through the various cooling jackets of the engine and its auxiliaries. In this way, the body of water acts a heat exchanger for the engine.
This arrangement provides extreme simplicity and a compact arrangement, which is particularly important in connection with outboard motors. However, the utilization of water from the body of water in which the watercraft is operating for engine cooling can present some problem. For example, many times the body of water may contain certain foreign materials that can cause damage to the engine cooling system. This is particularly true when operating in marine environments wherein the salt in the water could cause corrosion of the engine cooling jacket.
Therefore, it has been the practice to provide some form of flushing system for flushing the cooling jacket of the engine when the engine is taken out of service or even for flushing it periodically during times when it is relatively continuous service.
A wide variety of types of flushing systems have been provided and most of them are relatively complicated in nature. For example, some of these flushing systems employ cuffs or other types of devices that fit around the water inlet opening in the lower unit. Thus, in order to flush the engine cooling jacket, a substantial amount of water must be passed through the system. Also, this flushing path may not ensure that all of the portions of the engine cooling jacket are clean.
Other types of devices have been proposed that require attachment of connections to the actual engine body in order to flush its cooling jacket. Although these devices have advantages over the cuff-type flushing arrangement, it is necessary to remove the protective cowling in order to flush the system. In addition, the flushing communication with the cooling system is not always in a area where it will ensure that the jackets are entirely flushed nor that minimum amounts of water may be required for the flushing.
It is, therefore, a principal object of this invention to provide an improved coolant flushing system for an outboard motor.
It is a further object of this invention to provide a flushing system for the cooling jacket of an outboard motor which does not require either external attachments to the outboard motor or removal of the protective cowling and which nevertheless will provide efficient flushing.
It is a further object of this invention to provide an improved flushing system for the cooling jackets of an outboard motor wherein the flushing connection is made in such a way as to minimize the amount of water required for the flushing operation while, at the same time, ensuring complete flushing of the cooling jackets.
It is a further object of this invention to provide an improved outboard motor construction that employs a built-in flushing arrangement that does not require special fittings, special connections or removal of the protective cowling to effect flushing.
In connection with outboard motor cooling systems, it is generally the practice also to employ a device called a "tell tale". This is an arrangement wherein a portion of the cooling water is bled back to the body of water in which the watercraft is operating from a location where the operator of the outboard motor can visually ascertain that coolant is flowing through the engine cooling jacket. Frequently, the location and positioning of the tell tale's is such that they do not cooperate very effectively with the flushing system and may in fact result in bypassing some of the cooling jackets during the flushing operation. It is, therefore, a still further object of this invention to provide an improved arrangement for flushing an outboard motor engine without interfering with the tell tale operation and without unduly complicating the plumbing connections to the cooling jacket that are required for a flushing operation.